Unitary air conditioning system

ABSTRACT

A unitary air conditioning system comprises an outdoor unit including a compressor for compressing refrigerant, an outdoor heat exchanger for heat exchange of refrigerant, and an expander connected to the outdoor heat exchanger, for expanding refrigerant; a duct installed in each zone of a building; a plurality of central blower units, each unit having a heat exchanger connected to the outdoor unit by a refrigerant pipe and a blower for supplying the air heat-exchanged by the heat exchanger to the duct; and a cooling/heating control unit for selectively distributing a refrigerant from the outdoor unit toward the heat exchangers of the plurality of central blower units and controlling cooling or heating operation for each zone of the building. Accordingly, the plurality of blower units are systematically operated according to a load of each zone inside the building, so that the cooling or heating operation can be effectively performed on each zone.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an air conditioning system, andparticularly, to a unitary air conditioning system provided with anoutdoor unit and a plurality of blower units connected to the outdoorunit, for cooling or heating each zone inside a building.

2. Description of the Background Art

In general, a unitary air conditioning system is a kind of centralheating and cooling system in which cool air or warm air is made byusing a heating and cooling device provided in a factory, an office, ahotel, a house or the like, and supplied to each zone through a pipe ora duct provided in a building.

In the unitary air conditioning system, to independently supply the coolor warm air to individual zones by distinguishing a zone requiringcooling or heating and a zone which does not so, a zone controller fordistributing the cool or warm air is installed on a duct, or a pluralityof heating and cooling devices are individually installedcorrespondingly to a plurality of zones.

As shown in FIGS. 1 and 2, a conventional unitary air conditioningsystem includes an outdoor unit 1 fixedly installed outside a building(a two-story building in the drawing); a supply duct 3 installed insideeach zone (Z1) and (Z2) in the building, for distributing the cool orwarm air to the zones (Z1) and (Z2); a return duct 4 for returning thecool or warm air in each zone (Z1) and (Z2); a central blower unit 2connected with the outdoor unit 1 by refrigerant pipes, for sending coolor warm air to the supply duct 3; and a zone controller 5 installedbetween the central blower unit 2 and the supply duct 3 and between thecentral blower unit 2 and the return duct 4, for controlling a supplyand a return of the air to and from the zones (Z1) and (Z2).

The outdoor unit 1 includes a compressor 1 a for compressingrefrigerant; a first heat exchanger 1 b connected to the compressor 1 aby refrigerant pipes, for heat exchange between refrigerant and ambientair; an expander 1 c for expanding volume of refrigerant and reducingpressure of refrigerant; a four way valve 1 d disposed adjacent to thecompressor 1 a, for circulating a compressed refrigerant discharged fromthe compressor 1 a according to a heating cycle or a cooling cycle; andan accumulator 1 e disposed in the vicinity of a refrigerant inlet ofthe compressor 1 a, for filtering a liquefied refrigerant.

The central blower unit 2 includes a second heat exchanger 2 a connectedto the compressor 1 a and the expander 1 c by refrigerant pipes,respectively; and a supply fan (not shown) disposed adjacent to thesecond heat exchanger 2 a, for supplying the cool or warm air to thesupply duct 3.

A plurality of discharge openings 3 a are formed at the supply duct 3 tosupply the cool or warm air to a zone requiring cooling or heating, anda plurality of suction openings 4 a through which the air of each zoneis sucked are formed at the return duct 4.

The zone controller 5 is composed of valve 5 a, 5 b, 5 c and 5 d forselectively supplying the cool or warm air to each zone (Z1) and (Z2),wherein the valves are installed at the supply duct 3 and the returnduct 4 arranged in the corresponding zone (Z1) and (Z2). By the zonecontroller 5, the cool or warm air is distributed thus to be supplied toeach zone (Z1) and (Z2), or be selectively supplied to only one of thezones (Z1) and (Z2).

The conventional air conditioning system having such a structure isoperated as follows.

First, in case that a load detected in each zone (Z1) and (Z2) isgreater than a preset value, the cool or warm air is simultaneouslysupplied through the supply duct 3 of each zone (Z1) and (Z2). On theother side, in case that just one load of one of the zones (Z1) and (Z2)is greater than a preset value, the cool or warm air is supplied throughthe supply duct 3 of the corresponding zone, which requires cooling orheating, by operation of the zone controller 5.

For example, during the cooling operation, a refrigerant compressed bythe compressor 1 a of the outdoor unit 1 is condensed in the first heatexchanger 1 b of the outdoor unit 1, and the condensed refrigerantpasses through the expander 1 c and then passes through the second heatexchanger 2 a of the central blower unit 2, thereby exchanging its heatwith the air introduced through the return duct 4. The air cooled insuch a manner moves to the supply duct 3 by a supply fan (not shown).

At this time, the zone controller 5 is operated according to a load ofeach corresponding zone (Z1) and (Z2), thereby cooling the zone thatrequires cooling.

Meanwhile, during the heating operation, a flow of the refrigerant isconverted by operation of the four way valve 1 d, and a heating cycle iscarried out as a reverse cycle of the cooling cycle.

However, the conventional air conditioning system constructed andoperated as described above has following problems.

First, a zone controller for controlling a return and supply of airshould be additionally installed when the cool or warm air is to be moreintensively supplied to a zone having high loads, such as a kitchen, asun room, an exercise room or the like in the building. However,operations for an additional installation of the duct and the zonecontroller are complicated.

Also, to independently correspond to a load of each zone, a plurality ofoutdoor units and a plurality of central blower units may be installedcorresponding to the number of zones. However, it may cause an increasein cost, which is very inefficient.

SUMMARY OF THE INVENTION

Therefore, an object of the present invention is to provide a unitaryair conditioning system capable of effectively performing cooling orheating operation corresponding to a load of each zone by being providedwith a cooling/heating control unit for selectively distributing arefrigerant from an outdoor unit to each blower unit for performingcooling or heating operation on each zone.

Another object of the present invention is to provide a unitary airconditioning system capable of individually cooling or heating aspecific zone having high loads or having no duct by employing anindividual cooling and heating system within a central cooling andheating system performing heating and cooling operation on each zone ina building.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described herein,there is provided a unitary air conditioning system comprising anoutdoor unit including a compressor for compressing refrigerant, anoutdoor heat exchanger for heat exchange of refrigerant, and an expanderconnected to the outdoor heat exchanger, for expanding refrigerant; aduct installed in each zone of a building; a plurality of central blowerunits, each unit having a heat exchanger connected to the outdoor unitby a refrigerant pipe and a blower for supplying the air heat-exchangedby the heat exchanger to the duct; and a cooling/heating control unitfor selectively distributing a refrigerant from the outdoor unit towardthe heat exchangers of the plurality of central blower units andcontrolling cooling or heating operation for each zone of the building.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described herein,there is provided a unitary air conditioning system comprising anoutdoor unit including a compressor for compressing refrigerant, anoutdoor heat exchanger for heat exchange of refrigerant, and an expanderconnected to the outdoor heat exchanger, for expanding refrigerant; aduct installed in each zone of a building; a central blower unit havinga heat exchanger connected to the outdoor unit by a refrigerant pipe,and a blower for supplying the air heat-exchanged by the heat exchangerto the duct; an individual blower unit including a heat exchangerconnected to the outdoor unit by a refrigerant pipe and a fan forsending the air heat-exchanged by the heat exchanger, and disposed in azone inside the building, for individually cooling or heating the zone;and a cooling/heating control unit for selectively distributing therefrigerant from the outdoor unit toward the heat exchangers of thecentral blower unit and the individual blower unit and controllingcooling or heating operation for each zone of the building.

The foregoing and other objects, features, aspects and advantages of thepresent invention will become more apparent from the following detaileddescription of the present invention when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute aunit of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention.

In the drawings:

FIG. 1 is a schematic view showing one example of a conventional airconditioning system;

FIG. 2 is a block diagram showing the air conditioning system of FIG. 1;

FIG. 3 is a schematic view showing an air conditioning system inaccordance with an embodiment of the present invention;

FIG. 4 is a block diagram showing the air conditioning system of FIG. 3;and

FIG. 5 is a control block diagram of the air conditioning system of FIG.3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings.

As shown in FIGS. 3 to 5, a unitary air conditioning system inaccordance with an embodiment of the present invention includes anoutdoor unit 110 installed outside a building; a plurality of ducts 121and 122 installed at each zone (Z1) and (Z) in the building, fordistributing cool or warm air inside the building; a central blower unit120 connected to the outdoor unit 110 and installed inside or outsidethe building, for supplying the cool or warm air inside the buildingthrough the ducts 121 and 121; an individual blower unit 140 connectedto the outdoor unit 110 and installed at a specific zone (Z3) in thebuilding, such as a kitchen or the like, for individually supplying thecool or warm air to the specific zone; and a cooling/heating controlunit 300 for selectively distributing a refrigerant from the outdoorunit 110 toward the central blower unit 120 and the individual blowerunit 140 and controlling the cooling and heating operation for each zone(Z1), (Z2) and (Z3).

The outdoor unit 110 includes a compressor 111 for compressingrefrigerant; an outdoor heat exchanger 113 for heat exchange betweenrefrigerant and ambient air; a four way valve 117 for circulating therefrigerant discharged from the compressor 111 according to a cooingcycle or a heating cycle; an accumulator 118 disposed in the vicinity ofa refrigerant inlet of the compressor 111, for filtering a liquefiedrefrigerant; an expander 114 connected to the outdoor heat exchanger113, for expanding volume of refrigerant and reducing pressure ofrefrigerant; and a fan 119 disposed adjacent to the outdoor heatexchanger 113.

The plurality of ducts 121 and 122 are divided to be arranged in aplurality of zones (Z1) and (Z2) in the building, respectively, and arecomposed of a supply duct 121 having a plurality of discharge openings121 a; and a returned duct 122 having a plurality of suction openings122 a.

Preferably, the number of central blower units 120 corresponds to thenumber of zones (Z1) and (Z2), and the central blower units 120 areinstalled in parallel, so that the cool or warm air can be independentlysupplied to the zones (Z1) and (Z2) in the building. In the presentembodiment, a two-story building is divided into a first zone (Z1) onthe first story and a second zone (Z2) on the second story, and an airconditioning system in which two central blower units corresponding tothe first and second zones (Z1) and (Z2) are installed in parallel willbe now be described.

The central blower unit 120 includes a first heat exchanger 123connected to the outdoor unit 110 through a first refrigerant pipe 150;and a blower 125 for supplying the air heat-exchanged by the first heatexchanger 123 to the supply duct 121.

The individual blower unit 140 includes a second heat exchanger 141connected to the outdoor unit 110 by the second refrigerant pipe 160;and a blower fan 142 for sending the air heat-exchanged by the secondheat exchanger 141.

The individual blower unit 140 is disposed in a zone where there arerelatively high loads or a duct is not installed, such as a kitchen or asun room inside the building, and subsidiarily cools or heats the zone(Z3).

Various types, such as a panel type, cabinet type, a slim type, aceiling type, or the like can be employed for the individual blower unit140, and the number of individual blower units 140 may be installedcorrespondingly to the number of zones requiring subsidiary cooling orheating.

The cooling/heating control unit 300 includes a plurality of firsttemperature controllers 124 installed inside each zone (Z1) and (Z2) inthe building, for detecting a temperature of each zone (Z1) and (Z2) andreceiving a set temperature value of a user; a second temperaturecontroller 144 installed at the individual blower unit 140, forreceiving a set temperature value of the user and detecting atemperature of a room where the individual blower unit 140 is installed;control valves 151, 152, 161 and 162 respectively installed at the firstand second refrigerant pipes 150 and 160; and a control unit 301connected with the first temperature controller 124 and the secondtemperature controller 144, for comparing room temperatures inputtedfrom the first and second temperature controller 124 and 144 with a settemperature, and controlling operation of the control valves 151, 152,161 and 162 and the compressor 111.

The first and second refrigerant pipes 150 and 160 are opened and closedby the operation of the control valves 151, 152, 161, and 162. Accordingto this, the operation of the central blower unit 120 and the individualblower unit 140 is controlled, and the cooling or heating for each zone(Z1), (Z2) and (Z3) in the building is selectively controlled.

Meanwhile, preferably, the control unit 301 is directly connected withthe second temperature controller 144 through a communication line.

Operation of the air conditioning system having such a structure inaccordance with an embodiment of the present invention will now bedescribed. Here, a case that the air conditioning system performs thecooling operation will be explained as an example.

First, if a temperature value of each zone (Z1), (Z2) and (Z3), which isdetected from the first and second temperature controllers 124 and 144of the cooling/heating control unit 300, and a temperature value set bya user are inputted to the control unit 301, the control unit 301compares a room temperature of each zone (Z1), (Z2) and (Z3) with theset value of the user.

At this time, if the room temperatures of the zones (Z1), (Z2) and (Z3)exceed the set value, the control unit 301 outputs a signal for drivingthe compressor 111 and simultaneously, outputs a signal for opening thecontrol valves 151, 152, 161 and 162.

Here, if all the temperature values of the zones (Z1), (Z2) and (Z3)exceed the set value, the control unit 301 opens all of the controlvalves 151, 152, 161 and 162. And if just one temperature value of oneof the zones (Z1), (Z2) and (Z3) exceeds the set value, the control unit301 opens only one set of control valves that are connected to theblower unit related to the corresponding zone, of the control valves151, 152, 161 and 162.

For example, if a load of the first or second zone (Z1) and (Z2) exceedsa preset value and a load of the third zone (Z3) is smaller than thepreset value, that is, if the cooling is required only for the first orsecond zone (Z1) and (Z2), is the compressor 111 is driven by a signalof the control unit 301, the control valves 151 and 152 connected to thecentral blower unit 120 related to cooling operation for the first orsecond zone (Z1) and (Z2) are opened, and the control valves 161 and 162connected to the individual blower unit 140 related to cooling operationfor the third zone (Z3) maintains a closed state.

And a refrigerant compressed by the compressor 111 is introduced to theoutdoor heat exchanger 113 through the four way valve 117 to becondensed, and the condensed refrigerant passes through the expander114, thereby being expanded, reducing the pressure. And the refrigerantexpanded in the expander 114 moves to the first heat exchanger 123 andis evaporated to thereby exchange its heat with ambient air of the firstheat exchanger 123. And then, the air moves toward the outdoor unit 110.

And the air heat-exchanged by the first heat exchanger 123 is dischargedto supply duct 121 by the blower 125 and to the first and second zones(Z1) and (Z2) through the discharge openings 121 a. And the air havingcompleted its cooling operation in the first or second zone (Z1) and(Z2) is introduced to the return duct 122 through the suction openings122 a, is reintroduced to the central blower unit 120 and passes throughthe first heat exchanger 123, thereby being cooled again. Such processesare repeated, so that the central cooling operation is performed on thefirst or second zone (Z1) and (Z2).

Meanwhile, if the sum of loads of the third zone (Z3) having speciallyhigh loads, such as a kitchen, a sun room or the like is greater than apreset value, the second refrigerant pipe 160 connecting the individualblower unit 140 with the outdoor unit 110 is opened by operation of thecontrol valves 161 and 162. According to this, the refrigerant havingpassed through the outdoor heat exchanger 113 and the expander 114 isintroduced to the second heat exchanger 141 of the individual blowerunit 140 and exchanges it heat with ambient air of the second heatexchanger 141. And the air heat-exchanged by the second heat exchanger141 is sent to the third zone (Z3) by the fan 141, thereby individuallycooling the third zone (Z3).

Meanwhile, the control unit 301 compares a room temperature of each zone(Z1), (Z2) and (Z3) with a set value. If all the room temperatures ofthe zones (Z1), (Z2) and (Z3) are lower than the set value, the controlunit 301 outputs a signal for stopping the compressor 111 andsimultaneously outputs a signal for closing the control valves 151, 152,161 and 162. According to this, the compressor 111 is stopped, the firstand second refrigerant pipes 150 and 160 that respectively connects thecentral blower unit 120 and the individual blower unit 140 with theoutdoor unit 110 are closed, thereby stopping the cooing operation foreach zone.

In case that the air conditioning system in accordance with the presentinvention performs heating operation, a flow of a refrigerant is changedby the operation of the four way valve 116, and the refrigerant moves inreverse order of the above-described cooling cycle.

In the unitary air conditioning system in accordance with the presentinvention, a central blower unit performing central cooling or heatingoperation through a duct and an individual blower unit for individuallycooling or heating a specific zone where there are relatively high loadsor a duct is not installed are installed to be connected in parallel toone outdoor unit. Accordingly, cooling or heating operation can beperformed zone by zone using a duct and simultaneously, individualcooling or heating operation can be additionally performed on a specificzone, so that a cost is lowered and the cooling and heating operationfor the building can be efficiently carried out.

In addition, by providing a cooling/heating control unit which cancirculate a refrigerant by distributing the refrigerant between oneoutdoor unit and a plurality of blower units, the plurality of blowerunits are systematically operated according to a load of each zone in abuilding. Accordingly, the cooling or heating operation for each zonecan be effectively carried out.

As the present invention may be embodied in several forms withoutdeparting from the spirit or essential characteristics thereof, itshould also be understood that the above-described embodiments are notlimited by any of the details of the foregoing description, unlessotherwise specified, but rather should be construed broadly within itsspirit and scope as defined in the appended claims, and therefore allchanges and modifications that fall within the metes and bounds of theclaims, or equivalence of such metes and bounds are therefore intendedto be embraced by the appended claims.

1. A unitary air conditioning system comprising: an outdoor unitincluding a compressor for compressing refrigerant, an outdoor heatexchanger for heat exchange of refrigerant, and an expander connected tothe outdoor heat exchanger, for expanding refrigerant; a duct installedin each zone of a building; a plurality of central blower units, eachunit having a heat exchanger connected to the outdoor unit by arefrigerant pipe and a blower for supplying the air heat-exchanged bythe heat exchanger to the duct; and a cooling/heating control unit forselectively distributing a refrigerant from the outdoor unit toward theheat exchangers of the plurality of central blower units and controllingcooling or heating operation for each zone of the building.
 2. Thesystem of claim 1, wherein the cooling/heating control unit comprises: aplurality of temperature controllers installed inside each zone in thebuilding, for detecting a temperature of each zone and receiving a settemperature value of a user; control valves installed at refrigerantpipes for respectively connecting the outdoor unit with the plurality ofcentral blower units, for controlling a flow rate of a refrigerant; anda control unit connected to the temperature controllers, for comparing aroom temperature inputted from each temperature controller with a settemperature value of a user, and controlling the control valves.
 3. Aunitary air conditioning system comprising: an outdoor unit including acompressor for compressing refrigerant, an outdoor heat exchanger forheat exchange of refrigerant, and an expander connected to the outdoorheat exchanger, for expanding refrigerant; a duct installed in each zoneof a building; a central blower unit having a heat exchanger connectedto the outdoor unit by a refrigerant pipe, and a blower for supplyingthe air heat-exchanged by the heat exchanger to the duct; an individualblower unit including a heat exchanger connected to the outdoor unit bya refrigerant pipe and a fan for sending the air heat-exchanged by theheat exchanger, and disposed in a zone inside the building, forindividually cooling or heating the zone; and a cooling/heating controlunit for selectively distributing the refrigerant from the outdoor unittoward the heat exchangers of the central blower unit and the individualblower unit, and controlling cooling or heating operation for each zoneof the building.
 4. The system of claim 3, wherein the cooling/heatingcontrol unit comprises: a plurality of first temperature controllersinstalled inside each zone in the building, for detecting a temperatureof each zone and receiving a set temperature value of a user; a secondtemperature controller installed at the individual blower unit, forreceiving a set temperature value of the user and detecting atemperature of a room where the individual blower unit is installed;control valves respectively installed at refrigerant pipes thatrespectively connect the outdoor unit with the central blower units anda refrigerant pipe that connects the outdoor unit with the individualblower unit; and a control unit connected with the first temperaturecontrollers and the second temperature controller, for comparing theroom temperatures inputted from the first and second temperaturecontrollers with the set temperature value, and controlling the controlvalves.
 5. The system of claim 4, wherein the second temperaturecontroller and the control unit are directly connected to each otherthrough a communication line.